Direct synthesis of mesoporous TiO2 and its catalytic performance in DBT oxidative desulfurization

Abstract This paper presents a synthesis process of mesoporous titanium dioxide materials (TiO 2 ) with tetrabutyl titanate as the precursor at ambient conditions. Phosphotungstic acid (PWA) was used as the catalyst, and quaternary ammonium bromide including octadecyltrimethylammonium bromide (STAB), cethyltrimethylammonium bromide (CTAB), (1-tetradecyl)trimethylammonium bromide (TTAB), and dodecyltrimethylammonium bromide (DTAB) as the structure-directing agent. STAB was found to be the best structure-directing agent. The calcined mesoporous TiO 2 materials by STAB were characterized by X-ray fluorescent spectroscopy (XRF), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectra, transmission electron microscopy (TEM)) and nitrogen adsorption/desorption measurements. The nitrogen adsorption/desorption isotherms exhibit the characteristics of mesoporous structure. TEM results indicate that the disordered wormhole-like mesostructure without discernible long-range order is formed by the agglomerization of TiO 2 nanoparticles. The TiO 2 materials exhibit good performance in DBT oxidation. The influence of reaction temperature, catalyst concentration, H 2 O 2 concentration, and initial DBT concentrations on the oxidation of DBT was examined in detail. DBT removal from a 300 ppm dibenzothiophene mixture was as high as 98% within 2 min reaction.